GB487634A - Improvements in pantographic copying and engraving machines - Google Patents

Abstract

487,634. Copying milling - machines. DECKEL, F. Aug. 4, 1937, No. 21527. Convention date, Aug. 5, 1936. [Class 83 (iii)] In a pantographic copying or engraving machine having a pantograph system lying in and movable in a vertical plane, the vertical or horizontal thrusts are partially balanced by elastic means or weights and positive control means such as a screw spindle may be provided for moving the horizontally slidable parts. The machine comprises a bar 3 pivoted to a frame 1 on a vertical axis 2 and provided with guides 4 for slides 5, 6 carrying the vertically movable tool holder 7 and tracer holder 8 respectively. A pantograph 12 .. 15 is pivoted on a horizontal axis 16 on the bar 3 and is connected at 17, 18 to the tool and tracer holders respectively, and the latter is controlled by a handle 19. The balancing may be effected by an adjustable weight 21 on an arm 20 rigid with the link 12 of the pantograph, or by springs or weights 22, 23 attached to the tool and tracer holders and to the slides 5, 6 or other vertically fixed parts, or by both weights and springs. For counteracting the horizontal thrust of the pantograph, a hand operated screw spindle may be journalled on the bar so as to act on the slide 5 for moving it along the bar, or alternatively a weight 25, Fig. 3, may be mounted on an arm 12a in line with the link 12, and springs 26, 27 may act between the slides 5, 6 and the arm, or springs 28 between movable parts of the pantograph. In another modification, a compression spring enclosed in a telescopic tube is arranged between the superimposed points 31, 32 of the pantograph.